Usage:
basalt of Shumaker Creek (informal) in Eckler Mountain Member of Wanapum Basalt of Columbia River Basalt Group (OR*,WA*)
basalt of Shumaker Creek (informal) in Wanapum Basalt of Columbia River Basalt Group (OR)
basalt of Shumaker Creek (informal) in Eckler Mountain Member of Wanapum Basalt of /Yakima basalt subgroup [informal] of Columbia River Basalt Group (OR*,WA*)
Also called flows of Shumaker Creek (informal).
Informal. The rank or lithologic term should not be capitalized. [Yakima basalt subgroup considered informal and should not be capitalized. "Subgroup" not recognized as a formal stratigraphic rank term (CSN, 1933; ACSN, 1961, 1970; NACSN, 1983, 2005, 2021). Columbia River Basalt Group adopted by the ID, OR, and WA Geol. Surveys, and the USGS (rules suspended).]
Geologic age:
late Tertiary (middle Miocene)*
Type section, locality, area and/or origin of name:
Named for a flow prominently exposed in roadcuts above the basalt of Dodge at the head of Shumaker Creek, in extreme southeast corner of sec. 11, T. 7 N., R. 45 E., Black Butte quadrangle, Asotin Co., WA (Swanson and others, 1979; see fig. 1, loc. 12).
AAPG geologic province:
Eastern Columbia basin*
For more information, please contact Nancy Stamm, Geologic Names Committee Secretary.
Asterisk (*) indicates published by U.S. Geological Survey authors.
"No current usage" (†) implies that a name has been abandoned or has fallen into disuse. Former usage and, if known, replacement name given in parentheses ( ).
Slash (/) indicates name conflicts with nomenclatural guidelines (CSN, 1933; ACSN, 1961, 1970; NACSN, 1983, 2005, 2021). May be explained within brackets ([ ]).